gracias por responder, mi verdadero problema no es hacer ping, sino hacer nmap, me sale:
Starting Nmap 6.46 (
http://nmap.org ) at 2014-07-14 01:52 CEST
Nmap scan report for dant3sis-c6f4b1.home (192.168.x.xx)
Host is up (0.029s latency).
All 1000 scanned ports on dant3sis-c6f4b1 (192.168.x.xx) are filtered
MAC Address: 00:xx:14:xx:60:xx (Intel Corporate)
Nmap done: 1 IP address (1 host up) scanned in 31.40 seconds
y sin embargo haciendolo al sistema normal me los da sin problemas